Top latch unit



y 1967 4 w. o. BALDUCCII 3,319,986

TOP LATCH UNIT Filed Feb. 18. 1965 INVEN.TOR. Wkz. TE}? 0; BfiLDl/CC/ Patented May 16, 1967 3,319,986 TOP LATCH UNIT Walter O. Balducci, New Britain, Conn, assignor to Emhart Corporation, a corporation of Connecticut Filed Feb. 18, 1965, Ser. No. 433,712 6 Claims. (Cl. 292-92) This invention relates to a top latch unit for emergency-exist door locks of the vertical rod type and more particularly to improvements in the top latch unit shown and described in the copending application of Nicholas A. Welch, Ser. No. 394,275, filed Sept. 3, 1964, and the divisional application thereof, Ser. No. 620,566, filed Oct. 28, 1966.

As is well known to those skilled in the art, emergency exist door locks of the vertical rod type generally include top and bottom latch units that are adapted to be mounted on the inner face of a door adjacent the upper and lower edges thereof, respectively, and an operating unit that is designed to be mounted on said face of the door intermediate the latch units. The operating unit is operatively connected to the latch units by rigid rods or the like that extend vertically on the door and is actuated by a panic-bar that generally extends across substantially the entire width of the door. The latch units contain latch-bolts that are usually designed to project beyond the adjacent edges of the door into engagement with keepers recessed into the head jamb and threshold of the door opening for retaining the door in closed position. When the panic-bar is actuated, the latchbolts are retracted out of engagement with their respective keepers to allow the door to be opened.

In many installations where it is desired to use such vertical rod emergency-exit locks, there is insufficient space between either the upper or the lower edge of the door and the adjacent ceiling or floor surface, or both, to accommodate the respective latchbolt in its projected position. It is therefore common practice to provide means in such locks, usually in the top latch unit, for holding the latchbolts in retracted position after the door has been opened and for automatically releasing the latchbolts when the door is returned to its fully closed position. This not only prevents the latchbolts from dragging along the ceiling or floor and causing unsightly marks thereon as the door swings between its closed and open positions, but also insures that the latch-bolts will not interfere with the closing of the door or cause objectionable noise as the door approaches closed pOSition. In order to satisfy the functional requirements of potential users of vertical rod emergency-exit locks, however, such locks are also generally made available without the latchbolt holdback feature referred to above.

Prior to the development of the top latch unit disclosed in the above-identified copending application of Nicholas A. Welch, it was generally necessary for manufacturers to furnish different t-op latch units for holdback and nonholdback applications. This not only increased the cost of the locks, but also presented numerous problems in both production and sales. Moreover, it was not possible to convert such top latch units from one function to the other in the field. While the top latch unit of the aforesaid copending applications overcame many of the disadvantages inherent in prior latch units by virtue of the fact that the same latch structure could be used for both holdback and non-holdback applications with the exception of one simple part, it was found that it lacked the positiveness of operation that is mandatory in devices of this type.

It is therefore the primary object of this invention to provide atop latch unit for vertical rod emergency-exit door locks which may readily be adapted for holdback or non-holdback applications and possesses the requisite operating characteristics.

A further object of the invention is to provide such a top latch unit which can be converted from a holdback to a non-holdback type in the field with the substitution of but one simple part.

Another and very important object of the invention is to provide a top latch unit which does not require close tolerances in manufacture, fine adjustment or highly accurate construction in order to insure its positive operation.

The foregoing and other objects and advantages of the invention will be apparent from the following description and the accompanying drawings in which:

FIG. 1 is a plan view of a top latch unit embodying the present invention with the cover thereof being shown in section, said unit being adapted for latchbolt hol-dback operation.

FIG. 2 is a side view of said latch unit, also with the cover thereof shown in section.

FIG. 3 is a sectional side view further illustrating said latch unit.

FIG. 4 is a front view thereof with the cover again shown in section.

FIG. 5 is a sectional side view of said top latch unit illustrating the operation of the latchbolt holdback means,

FIG. 6 is a similar view of said top latch unit, but showing same adapted for non-holdback operation.

FIG. 7 is an isometric View of the novel reversible yoke member utilized in my improved latch unit.

As illustrated in the drawings, my improved top latch unit includes an elongated frame 5 which is adapted to be fastened to the inner face of a door adjacent the upper edge thereof and has side walls 6-6 with forward extensions 7-7 at the top thereof. A latchbolt 8 of generally bell-crank shape is pivotally mounted between said extensions by means of a pivot pin 9 and said latchbolt has a stop 10 formed thereon which engages an abutment 11 on the frame to limit movement of said latchbolt to its projected position (see FIG. 3) wherein it projects beyond the upper edge of the door for engagement with a keeper recessed into the head jamb of the door frame.

A slide 12 is slidably retained in said frame by inturned flanges 13-13 on the said side walls 6-6 and has opposed, arcuate, cam slots 14 in the side walls thereof which receive rollers 15-15 projecting from the opposite sides of the latchbolt. A U-shaped yoke 16 straddles the side walls of the frame 5 and is detachably secured thereto by means of opposed, inwardly extending ears 17-17 which snap into openings 18-13 in said side walls. The front portion of said yoke has a centrally located threaded hole 19 therethrough to receive either a screw 20 or a screw 20a (see FIG. 6) for securing a cover 21 in position over said frame 5 and against the face of the door.

The slide 12 of said top latch unit carries a connector 22 that is secured to the slide by a pin 23 which extends through holes in the opposite side walls of said slide and into guide slots 25 in the side walls of the frame, said connector being provided for securing the upper vertical rod 26 to the slide 12, all as shown and described in the above-identified copending applications.

When the top latch unit is installed on a door and operatively connected to the other components of the lock, the slide 12 is normally gravitally biased into its lowermost position, shown in FIGS. 2 and 4, wherein the latchbolt 8 is retained in fully projected position through the coaction of the cam slots 14-14 and the rollers 15-15. Operation of the panic-bar will raise the vertical rod 26 and the slide 12 thereby urging the latchbolt to either its fully or partially retracted position, as shown in FIGS.

5 and 6, respectively, depending on whether the latch unit has been conditioned for holdback or non-holdback operation. In either case, however, the latchbolt will always be retracted for enough to disengage it from its keeper to allow the door to be Opened.

The latchbolt holdback means provided in the top latch unit include downwardly facing abutments on the slide 12 which are defined by flats 27-27 at the lower ends of the upper edges of the cam slots I l-14. When the latchbolt 8 is moved to its fully retracted position through operation of the panic-bar, as shown in FIG. 5, the rollers -15 will be disposed under said flats and will prevent the slide 12 from moving downwardly to its normal position when the panic-bar is released. Hence, the latchbolt 8 will be retained in its fully retracted position when the door is opened.

It will be understood that the bottom latch unit, not shown, is connected to the top latch unit through the operating unit and a vertical rod similar to the rod 26 and operates simultaneously therewith. Thus, when the latchbolt of the top latch unit is retracted, the latchbolt of the bottom latch unit will also be retracted and, if the holdback means in the top latch unit is effective, the latchbolt of the bottom unit will be retained in retracted position until the top latchbolt is released.

I have provided by my invention a top latch unit in which the latchbolt holdback means may be rendered effective or ineffective by merely reversing the position of the yoke 16 with respect to the frame 5. As will be seen in FIG. 7, the yoke is provided with a centrally located notch 28 in one edge ofits front portion. This notch is adapted to receive a nose 30 formed on the inner end of the latchbolt when the yoke is positioned with the notch in register with said nose. The opposite edge of the yoke is not notched and therefore provides a stop portion 29 on the yoke which may be located in the path .of the nose.

When it is desired to render the latchbolt holdback means effective so that both the top and bottom latchbolts will be retained in retracted position when the door is open, the yoke 16 is assembled to the frame 5 with .the notch 28 at the bottom thereof, as shown in FIGS. '3 to 5. In this position, the notch 28 will provide a clearance for the nose 30 which will allow the latchbolt 'to be moved to its fully retracted position, shown in FIG. 5, wherein the flats 27-27 on the slide 12 will engage the rollers 15-15 and thereby hold the latchbolt in its retracted position as previously described.

In order to insure automatic release of the latchbolt 8 when the door closes, the screw is provided with a sliding plunger 31 and the keeper 32 for the said latchbolt is formed with a depending extension 33 which is engaged by and forces said plunger inwardly as the door approaches its closed position. This causes the plunger to move the latchbolt toward its projected position and release the rollers 15-15 from the flats 27-27 just as the door fully closes, whereupon the slide 12 will drop and urge the latchbolt into its projected, keeper engaging position.

When it is desired to render said holdback means inoperative, it is simply necessary to remove the cover 21 and detach the yoke 16 from the frame 5 by springing the leg portions of the yoke outwardly to remove the ears 17-17 from the openings 18-18. The yoke is then inverted and reassembled to the frame with the notch 28 located at the top, as shown in FIG. 6. When the yoke is in this position and the latchbolt is retracted, the nose 30 will strike the stop portion 29 of the yoke and prevent engagement of the rollers 15-15 with the flats 27-27, whereby the latchbolt will be returned to its projected position as soon as the panic-bar on the operating unit is released and the slide 12 drops.

When the top latch unit is adjusted for non-holdback operation, the plunger 31 and the keeper 32 are not required and may, if desired, be replaced by the screw 20-a and the keeper 34 shown in FIG. 6.

By utilizing the yoke 16 to control the point of stoppage of the latchbolt 8 rather than the cover retaining screw as in the latch unit of said copending applications, positiveness of operation is insured in both the holdback and non-holdback functions and the need for close manufacturing tolerances and fine adjustment during intallation is eliminated.

While I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention which is not to be limited to the details disclosed herein, but is to be accorded the full scope of the claims appended hereto so as to embrace any and all equivalent structures.

I claim:

1. A latch unit including a frame, a latchbolt pivotally mounted on said frame and movable between projected and retracted positions, a slide vertically reciprocably mounted in said frame and having a sidewall with a cam slot therein, a projection on said latchbolt extending into said cam slot whereby to cause movement of said latchbolt between its projected and retracted positions as said slide is reciprocated in said frame, abutment means on said slide engageable with said projection on the latchbolt for retaining said latchbolt in retracted position, a nose portion on said latchbolt, and a member adjustably mounted upon said frame and having a notch which in one position of said member receives said nose on the latchbolt to permit engagement of said abutment means on the slide with said projection and a stop portion which in another position of said member is engaged by the nose on the latchbolt to prevent engagement of said projection on the latchbolt with the abutment means on the slide.

2. A latch unit including a frame, a latchbolt pivotally mounted on said frame and movable between projected and retracted positions, a slide vertically reciprocably mounted in said frame and having parallel walls and opposed cam slots in said walls, projections on opposite sides of said latchbolt extending into said cam slots whereby to cause movement of said latchbolt between its projected and retracted positions as said slide moves in said frame, abutment means on said slide engageable with said projections on the latchbolt for retaining said latchbolt .in retracted position, a nose on said latchbolt, and a yoke member mountable on said frame in either of two inverted positions and having a notch which in one position of said yoke receives said nose on the latchbolt to permit engagement of the abutment means on the slide with the projections on the latchbolt and a stop portion which in the other position of said yoke is engageable by the nose on the latchbolt to prevent engagement of said projections on the latchbolt with the abutment means on the slide.

3. A latch unit including a frame, a latchbolt pivotally mounted on said frame and movable between projected and retracted positions, a slide slidable in said frame and having parallel walls and opposed cam slots in said walls, projections on opposite sides of said latchbolt extending into said cam slots whereby to cause movement of the latchbolt between its retracted and projected positions as said slide moves in said frame, abutment means on said slide engageable with the said projections on the latchbolt to retain said latchbolt in retracted position, a nose on said latchbolt, and a member adapted to be mounted on said frame in either of two inverted positions, said member in one position being disposed out of register with said nose on the latchbolt to permit engagement of said abutment means on the slide with said projections on the latchbolt and in the other position being disposed in the path of the nose in the latchbolt to prevent engagement of said projections on the latchbolt with the abutment means on the slide.

4. The subject matter set forth in claim 3 including means for moving said latchbolt to release said projections 5 thereon from said abutments on the slide and thereby permit the latchbolt to be returned to its projected position.

5. The subject matter set forth in claim 3 including a cover for said frame, a sleeve extending through said cover and threaded to said member for securing the cover over said frame, and a plunger slidable in said sleeve and adapted to move the latchbolt to release said projections from the abutment on the slide and thereby permit the return of the latchbolt to its projected position.

6. A latch unit including a frame, a latchbolt pivotally mounted on said frame and movable between projected and retracted positions, a slide slidable in said frame and having parallel Walls and opposed cam slots in said walls, projections on opposite sides of said latchbolt extending into said cam slots for causing movement of said latchbolt between its projected and retracted positions upon movement of said slide, abutment means on said slide engageable with said projections on the latchbolt to retain said latchbolt in retracted position, a nose on said latchbolt, a yoke member adapted to be detachably secured to said frame in either of two inverted positions, a cover for said frame, a screw extending through said cover and threaded to said yoke member for securing the cover to said frame, said yoke member having a notch in one edge thereof which in one position of said yoke member clears said nose on the latchbolt and permits engagement of said abutment means on the slide with said projections on the latch-bolt and a stop portion at the opposite edge thereof adapted, upon reversal of said yoke member relatively to the frame, to be engaged by the nose on the latchbolt to prevent engagement of said projections with the abutment means on the slide and thereby permit the return of the latchbolt to its projected position, a plunger slidable in saidscrew and adapted to release the latchbolt from said abutment means on the slide, a keeper for said latchbolt, and means on said keeper for actuating said plunger.

References Cited by the Examiner UNITED STATES PATENTS 2,945,372 7/1960 Reed 292-92 X 3,029,096 4/1962 Welch 292-92 X 3,149,864 9/1964 Foster 292-92 X EDWARD C. ALLEN, Primary Examiner. J. R. MOSES, Assistant Examiner. 

1. A LATCH UNIT INCLUDING A FRAME, A LATCHBOLT PIVOTALLY MOUNTED ON SAID FRAME AND MOVABLE BETWEEN PROJECTED AND RETRACTED POSITIONS, A SLIDE VERTICALLY RECIPROCABLY MOUNTED IN SAID FRAME AND HAVING A SIDEWALL WITH A CAM SLOT THEREIN, A PROJECTION ON SAID LATCHBOLT EXTENDING INTO SAID CAM SLOT WHEREBY TO CAUSE MOVEMENT OF SAID LATCHBOLT BETWEEN ITS PROJECTED AND RETRACTED POSITIONS AS SAID SLIDE IS RECIPROCATED IN SAID FRAME, ABUTMENT MEANS ON SAID SLIDE ENGAGEABLE WITH SAID PROJECTION ON THE LATCHBOLT FOR RETAINING SAID LATCHBOLT IN RETRACTED POSITION, A NOSE PORTION ON SAID LATCHBOLT, AND A MEMBER ADJUSTABLY MOUNTED UPON SAID FRAME AND HAVING A NOTCH WHICH IN ONE POSITION OF SAID MEMBER RECEIVES SAID NOSE ON THE LATCHBOLT TO PERMIT ENGAGEMENT OF SAID ABUTMENT MEANS ON THE SLIDE WITH SAID PROJECTION AND A STOP PORTION WHICH IN ANOTHER POSITION OF SAID MEMBER IS ENGAGED BY THE NOSE ON THE LATCHBOLT TO PREVENT ENGAGEMENT OF SAID PROJECTION ON THE LATCHBOLT WITH THE ABUTMENT MEANS ON THE SLIDE. 